Inducible nitric oxide synthase (iNOS) is the main rate-limiting enzyme of inflammatory response, which has a close bearing on the loss of dopaminergic neurons.7,8 However, few studies have been reported on the correlation between serum TNF-α and iNOS as well as cognitive impairment and disease burden in patients with schizophrenia. Here, NOS2 is linked to schizophrenia.